title: FOXL1, a novel candidate tumor suppressor, inhibits tumor aggressiveness and predicts outcome in human pancreatic cancer.
abstract: The forkhead box L1 (FOXL1) transcription factor regulates epithelial proliferation and development of gastrointestinal tract and has been implicated in gastrointestinal tumorigenesis in mouse models. However, the role of FOXL1 in pancreatic cancer development and progression remains to be elucidated. Here, we report that higher expression of FOXL1 is significantly associated with better clinical outcome in human pancreatic ductal adenocarcinoma (PDAC). A lower FOXL1 expression is correlated with metastasis and advanced pathologic stage of pancreatic cancer. Mechanistic analyses showed that overexpression of FOXL1 induces apoptosis and inhibits proliferation and invasion in pancreatic cancer cells, whereas silencing of FOXL1 by siRNA inhibits apoptosis and enhances tumor cell growth and invasion. Furthermore, FOXL1 overexpression significantly suppressed the growth of tumor xenografts in nude mice. FOXL1 promoted apoptosis partly through the induction of TNF-related apoptosis-inducing ligand (TRAIL) in pancreatic cancer cells. In addition, FOXL1 suppressed the transcription of zinc finger E-box-binding homeobox 1 (ZEB1), an activator of epithelial-mesenchymal transition, and the negative regulation of ZEB1 contributed to the inhibitory effect of FOXL1 on tumor cell invasion. Taken together, our findings suggest that FOXL1 expression is a candidate predictor of clinical outcome in patients with resected PDAC and it plays an inhibitory role in pancreatic tumor progression.
authors.affiliation: Pancreatic Cancer Unit, Laboratory of Human Carcinogenesis, Center for Cancer Research and Genetics Branch, National Cancer Institute, NIH, Bethesda, MD 20892, USA.
authors.forename: Geng
authors.initials: G
authors.lastname: Zhang
authors.forename: Peijun
authors.initials: P
authors.lastname: He
authors.forename: Jochen
authors.initials: J
authors.lastname: Gaedcke
authors.forename: B Michael
authors.initials: BM
authors.lastname: Ghadimi
authors.forename: Thomas
authors.initials: T
authors.lastname: Ried
authors.forename: Harris G
authors.initials: HG
authors.lastname: Yfantis
authors.forename: Dong H
authors.initials: DH
authors.lastname: Lee
authors.forename: Nader
authors.initials: N
authors.lastname: Hanna
authors.forename: H Richard
authors.initials: HR
authors.lastname: Alexander
authors.forename: S Perwez
authors.initials: SP
authors.lastname: Hussain
mesh_terms: D000818:Animals; D017209:Apoptosis; D015153:Blotting, Western; D021441:Carcinoma, Pancreatic Ductal / Q000401:mortality* / Q000517:prevention & control / Q000556:secondary; D002465:Cell Movement; D049109:Cell Proliferation; D047369:Chromatin Immunoprecipitation; D058750:Epithelial-Mesenchymal Transition; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques; D008156:Luciferases / Q000378:metabolism; D008297:Male; D051379:Mice; D008819:Mice, Nude; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000401:mortality* / Q000473:pathology / Q000517:prevention & control; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014407:Tumor Cells, Cultured; D000071799:Zinc Finger E-box-Binding Homeobox 1
chemical_list: C491001:FOXL1 protein, human; D051858:Forkhead Transcription Factors; D018398:Homeodomain Proteins; D012333:RNA, Messenger; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D014157:Transcription Factors; C486307:ZEB1 protein, human; D000071799:Zinc Finger E-box-Binding Homeobox 1; D008156:Luciferases